Some — and only some — cities are becoming more walkable because they understand that their sustainability (economic, health, and environmental) depends on it; or because they want to attract and retain young, educated adults; or because they are simply listening to the young or young-thinking adults in their administration; or some combination of the above. . . .
The General Theory of Walkability explains how, to attract pedestrians, a place has to provide a walk that is simultaneously useful, safe, comfortable, and interesting. This is extraordinarily difficult in most of our (driving) cities, and can only be accomplished when resources are concentrated where they can do the most good, rather than dispersed more evenhandedly across the city, which is the tendency. . . .
The Walkability Dividend is a concept advanced by the economist Joe Cortright and the non-profit CEOs for Cities, a group that has brought me into a small handful of downtowns with the understanding that all the events and amenities in the world won't make a difference in the absence of pedestrian culture. In his 2007 white paper "Portland's Green Dividend" [PDF], Cortright showed how that city's urban growth boundary, coupled with its investments in bike lanes and transit, resulted in a remarkable phenomenon: Portland's per-capita vehicle miles traveled peaked in 1996. Now Portlanders drive 20 percent less than the national average. This 20 percent results in financial savings and time savings that total almost four percent of GDP, ignoring all the wonderful externalities such as cleaner air and slimmer waistlines. Unlike driving dollars, 85 percent of which are sent out of town, much of those savings are spent locally, on housing and recreation. . . .Will Reston do enough to make its urban areas walkable--"provide a walk that is simultaneously useful, safe, comfortable, and interesting?"